The conventional cassette tape players are constituted such that an assembly of a motor and a number of gears are used in order to move the tape cassette, and said gears and another gear installed for opening/closing the door are meshed together, resulting in that the opening/closing of the door and the moving of the tape cassette are interlocked with each other.
But in order to interlock the opening/closing of the door and the moving of the tape cassette, a separate gear has to be installed, and this gear has to be meshed with other gears as mentioned above. In order to achieve such a constitution, the shape of the new gear has to be sufficiently considered, and the coupling manner between the said new gear and the other gears for moving the tape cassette has to be strictly studied. This makes the designing work more difficult, and further, the complication of the designing work is accompanied by consumption of much time.